JLG 15/20MSP Service Manual - Manual (Page 114)

SECTION 5 - MAST COMPONENTS
5-24 – JLG Lift – 3121231
10. Slide section-4 out the top of section-3 approxi-
mately one (1) foot.
11. Insert threaded ends of chain assembly (attached to
top of mast section-2), into the opening between
mast section-3 and mast section-4. Slide the
threaded ends through the holes in bottom anchor
plate attached to bottom of mast section-4. Loosely
thread two (2) 3/8"-16UNC nuts onto stud threads on
each chain until all slack is taken out of chain.
Chains will be adjusted later in assembly.
12. Assemble chain sheaves (for narrow chain assem-
bly) to top of mast section-4 as follows;
a. Locate the remaining sheave pin and slide the
wide tube spacer onto the pin shaft.
b. Place two (2) of the narrow chain sheave wheels
onto the sheave pin on each side of the wide
spacer.
c. Slide two (2) 1" flat washers onto each end of
sheave pin to outside of sheave wheels.
d. Place two (2) sheave pin support bars, one each
end of sheave pin to outside of space tubes.
Place a roll pin in the slots at each end of the
sheave pins and align with the cutouts in the pin
support bars.
e. Holding complete sheave wheel assembly, slide
assembly into top of mast section-4 and align
threaded holes in sheave pin support bars with
holes in mast rails.
f. Attach to top of mast section-4 using two (2) 3/
8"-16UNC x 1/2" long socket head-countersunk-
flathead cap screws, each side. Coat threads
with Loctite #171 and tighten.
13. Carefully slide mast section-4 into section-3 until
ends are even. Check to make sure chain assembly
(narrow chains) are seating properly in chain anchor
block chain sheave wheels attached to mast sec-
tion-3.
Mast Section 5 - Assembly
1. Locate the remaining mast section-5 (platform
mounting - mast section). Lay mast section on a flat
stable surface.
2. Attach the remaining chain bottom anchor plate
(one with threaded holes aligned at the outside of
bracket). Attach through set of holes in bottom of
mast section-5 with four (4) 1/4"-20UNC x 3/4" long
bolts, place a flatwasher under head of each bolt.
NOTE: The platform mounting section slide pads, are
assembled differently than the slide pads for the
other mast sections. Mast section-5 slide pads may
need to be assembled/disassembled several times in
order to determine the correct shim stock required
for proper fit.
Mast Section 4 - Chain Anchor Bracket
(Bottom of Mast)
1. Chain Anchor Bracket 3. Anchor Bolts/Washers (a)
2. Mast Section 4 4. Pot-Hole Actuator Bracket
Note: (a) Apply Loctite #242 to threads.
Mast Section 4 - Sheave Wheel Assembly
1. Support Bar Screws (a) 5. Wide Spacer
2. Pin Support Bars 6. Sheave Pin
3. Narrow Washers 7. Square Keys
4. Sheave Wheel Assys.
Note: (a) Apply Loctite #242 to threads.
1 1
2 2
3 3
5
6
7
4 4